Messenger RNA expression of RANTES in the urinary sediment of patients with lupus nephritis

Background: Lupus nephritis is characterized by intra-renal inflammation. Patients with systemic lupus erythematosus (SLE) showed abnormal T-cell expression of RANTES (regulated upon activation, normal T cell expressed) and its level in their serum. The authors studied the mRNA expression of RANTES in the urinary sediment of lupus patients. Methods: The authors studied 88 lupus patients, who were classified into active, remission and non-renal SLE groups according to the disease activity, 29 non-SLE and 10 healthy controls. Lupus activity was assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). Urinary mRNA expression of RANTES was studied by real-time quantitative polymerase chain reaction. Results: The expression of RANTES in urinary sediment was significantly elevated in active group (P < 0.001). Expression level of RANTES correlated with the SLEDAI score (r = 0.57; P < 0.001) and renal score in SLEDAI (r = 0.60; P < 0.001). In addition, urinary expression of RANTES had significant correlation with degree of proteinuria, serum creatinine, albumin and estimated glomerular filtration rate. Conclusion: The authors conclude that the mRNA expression of RANTES was elevated in the urinary sediment of patients with active lupus nephritis. Measurement of urinary mRNA expression may be a novel non-invasive method for the assessment of lupus disease activity and the severity of renal involvement.